1. Field of the Invention:
The present invention relates to protection means for preventing unauthorized entry through doors.
2. Description of the Prior Art:
Heretofore, various means have been developed for preventing or hindering access through a door or the like. See, for example, Zell, U.S. Pat. No. 79,047; Whitney, U.S. Pat. No. 158,876; Kern, U.S. Pat. No. 438,626; Dengler, U.S. Pat. No. 817,962; Bumpass, U.S. Pat. No. 1,413,573; Gettell, U.S. Pat. No. 1,535,770; Irwin, U.S. Pat. No. 1,792,537; Drenthe, U.S. Pat. No. 1,984,012; Sullivan, U.S. Pat. No. 2,018,098; Davis, U.S. Pat. No. 2,203,675; Lopina, U.S. Pat. No. 3,391,512; Arai, U.S. Pat. No. 3,863,762; and Dumortier, U.S. Pat. No. 4,175,781. None of the above patents disclose or suggest the present invention.